JPH0742871B2 - Vehicle slip control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle slip control device for controlling rotation of a drive wheel so that a frictional force between a tire of the drive wheel and a road surface during vehicle acceleration increases, and more particularly, to a drive system. The present invention relates to a vehicle slip control device that controls the rotation of wheels by the output of an engine.

[Prior Art] Starting and running on a road surface having a low coefficient of friction such as on ice or a snowy road is very dangerous because the vehicle may slip to the back or the vehicle spins due to slip of driving wheels. Therefore, in order to increase the friction coefficient between the tire and the road surface, spike tires, chains, etc. are conventionally installed.

A traction control system that suppresses slippage of the drive wheels has also been considered. As shown in Fig. 2, the slip ratio [(vehicle speed-drive wheel speed) / drive wheel speed] is set to -0.1 so that the road surface friction force is maximized. The engine output torque and the like are controlled so as to be controlled in the vicinity of -0.2. The engine output torque control is as follows. In other words, ignition delay control fuel cut fuel cut for each cylinder linkless throttle valve system, that is, throttle valve control when slip occurs inertia supercharging (volume efficiency) system As a result of suppressing engine output torque,
Acceleration slip is suppressed.

[Problems to be Solved by the Invention] As described above, various slip control methods are conventionally considered in the related art, and there is no acceleration loss or side slip of the vehicle body even when the driver makes a sudden acceleration. However, it is only considered that the engine output is suppressed when the wheels have an acceleration slip, and it is not considered to control the acceleration of the vehicle more optimally. It wasn't done.

Further, the one that simply cuts the fuel or retards the ignition timing at the time of the acceleration slip has a problem such as a sudden change in the operating state of the engine, an invention of vibration, or a stop, and a problem that the control range is narrowed. Therefore, the present invention aims to solve the above-mentioned problems, but in the sense of achieving the object, Japanese Patent Application No.
There is a technology described in Japanese Patent No. 184545, and when the intake air amount is controlled using the technology, the output of the internal combustion engine can be smoothly suppressed. However, in this technique, since the slip control range value is set to a predetermined constant range value in the entire speed range, the slip control range is narrowed or deviated from an appropriate value at middle and high speeds. It is an object of the present invention to solve the problem and further provide a slip control device for a vehicle capable of performing optimum slip control.

[Means for Solving Problems] Means configured according to the present invention for solving the above problems are as follows.
As shown in the basic configuration diagram of FIG. 1, an idle wheel rotation speed detecting means M2 for detecting the rotation speed of the idle wheel M1 of the vehicle, and a drive wheel rotation speed detecting means M4 for detecting the rotation speed of the drive wheel M3 of the vehicle. And the calculated value obtained from the detection value of the idle wheel rotation speed detection means M2 and the calculated value obtained from the detection value of the drive wheel rotation speed detection means M4.
And a slip range value setting means M6 for setting a predetermined slip range value including a predetermined upper limit slip value and a predetermined lower limit slip value.
If the slip value is equal to or greater than the predetermined upper limit slip value,
The output torque increasing / decreasing unit M8 of the engine M7 is controlled to reduce the output torque.On the other hand, when the slip value is equal to or less than the predetermined lower limit slip value, the output torque increasing / decreasing unit M8 of the engine M7 is controlled to increase the output torque. In the vehicle slip control device including the slip control means M9 for performing, the slip range value setting means M6 keeps the predetermined slip range value constant at a predetermined low vehicle speed state, and the predetermined slip range value at a predetermined medium and high vehicle speed. The gist is a slip control device for a vehicle, which is configured to widen the value in accordance with an increase in the vehicle speed.

The idle wheel rotation speed detecting means M2 in the present invention is for detecting the rotation speed of the left and right idle wheels M1 by a rotation speed sensor such as a magnetic pickup.

The drive wheel rotation speed detection means M4 is, for example, the left and right drive wheels M
3. The rotation speed sensor detects the rotation speed of the propeller shaft or speedometer cable.

The slip value calculating means M5 is for calculating the difference between the calculated value obtained from the rotation speed of the drive wheel M3 and the calculated value obtained from the rotation speed of the idle wheel M2.

The slip range value setting means M6, for example, sets a predetermined constant slip range value when the rotation speed of the idler wheel M1 is low, while widening the slip range value with an increase in the rotation speed when the rotation speed is medium to high. It is something to set.

The output torque increasing / decreasing unit M8 means, for example, controlling the ignition timing to increase / decrease the output torque, cut the fuel to increase / decrease the output torque, control the throttle valve to increase / decrease the output torque, and install a second throttle valve to inhale. Adjust the amount of air to increase or decrease the output torque, or decrease the output torque with the brake,
And so on.

The slip control means M9 controls the output torque increasing / decreasing unit M8, for example, controls the intake air amount of the engine M7 to adjust the output torque of the engine M7 so that the slip value is within a predetermined slip range value. To control.

[Operation] That is, in the vehicle slip control device of the present invention, the detection value of the slip value calculating means M5 is the slip range value setting means M6.
The output torque increasing / decreasing unit M8 is controlled by the slip control means M9 so that the output torque increasing / decreasing unit M8 is moved to within the predetermined slip range value set by. On the other hand, in the above predetermined slip range value, for example, when the rotational speed of the idler wheel M1 is low, the predetermined slip range value is constant, and at medium and high speeds, the predetermined slip range value is increased as the rotational speed of the idler wheel M1 increases. It is set to widen.

Therefore, for example, the slip range value is set to a constant predetermined range value at low vehicle speeds where the fluctuation of the vehicle speed is large, while the control range width is widened according to the speed at medium and high speeds, and is set to the slip range value that produces the most effect. can do.

Further, by keeping the slip range value constant in a predetermined low vehicle speed state, there is no need to improve the slip value calculation accuracy as the vehicle speed decreases.

Examples will be described below, but the examples of the present invention are not limited to these examples, and various embodiments are possible without departing from the scope of the invention.

[Embodiment] First, FIG. 3 is a schematic configuration diagram showing an engine periphery and a wheel portion of a vehicle equipped with a vehicle slip control device of the present embodiment, in which 1 is an engine, 2 is a piston, 3 is an ignition plug, 4 is an intake valve, 5 is a fuel injection valve, 6 is a surge tank,
7 is an air flow meter, and 8 is an air cleaner. In the present embodiment, the intake passage between the air flow meter 7 and the surge tank 6 adjusts the intake amount by interlocking with the accelerator pedal 9, which is conventionally provided.
In addition to the throttle valve 10, a second throttle valve 14 that is driven by a DC motor 12 and adjusts the intake air amount is provided in the same manner as the first throttle valve 10, and the first throttle valve 10 also has a throttle opening degree. Is provided with a first throttle opening sensor 16 that outputs an opening signal according to
Further, the second throttle valve 14 is provided with a second throttle opening sensor 17.

On the other hand, reference numerals 20 to 23 denote wheels of the vehicle, and 20 and 21 denote left and right drive wheels for driving the vehicle when the power of the engine 1 is transmitted via a transmission 25, a propeller shaft 26, and the like. Reference numerals 23 and 23 respectively represent left and right idler wheels that rotate as the vehicle runs. The left idle wheel 22 and the right idle wheel 23 are respectively provided with a left idle wheel speed sensor 27 and a right idle wheel sensor 28 for detecting their rotational speeds, and the right drive wheel 21 and the left drive wheel 20 are respectively provided. Is provided with a right drive wheel speed sensor 29a and a left drive wheel speed sensor 29b for detecting the respective rotation speeds.

Reference numeral 30 denotes a drive control circuit, which includes the first throttle opening sensor 16, the second throttle opening sensor 17, the left idle wheel speed sensor 27, the right idle wheel speed sensor 28, and the right drive wheel speed sensor.
The DC motor 12 that receives the detection signals from the left driving wheel speed sensor 29b and the left driving wheel speed sensor 29b and adjusts the opening degree of the second throttle valve 14 so that the maximum acceleration is obtained without causing an acceleration slip during vehicle acceleration. Slip control is executed in which a drive signal is output to control the engine output.

Here, in the present embodiment, the drive control circuit 30 is constructed by using a microcomputer, and if the description is advanced, the configuration of the drive control circuit 30 can be represented as shown in FIG. Reference numeral 31 in the figure is a central processing unit (CPU) that inputs and calculates data detected by the above-mentioned sensors in accordance with a control program and performs processing for driving and controlling the DC motor 12, and 32 is the control program, map, etc. Is a read-only memory (ROM) that stores the data of the above, 33 is a random access memory (RAM) in which the data from each of the above sensors and the data necessary for arithmetic control are temporarily read and written, and 34 is the waveform shaping circuit and each of the sensors. An input unit equipped with a multiplexer or the like for selectively outputting the output signal of the CPU 31 to the CPU 31, 35 is an output unit equipped with a drive circuit for driving the DC motor 12 in accordance with a control signal from the CPU 31, 36
Is a bus line that connects each element such as the CPU 31, ROM 32, etc., the input section 34, and the output section 35 and serves as a passage for various data. 37 is a power supply circuit for supplying power to each of the above sections.

Next, the slip control executed by the drive control circuit 30 configured as described above will be described based on the flowcharts of the control programs shown in FIGS. 5 and 6. This program is repeatedly executed by the CPU 31 when the starter switch of the vehicle is turned on.

First, when the processing of this program is started, initialization processing such as clearing the contents of the RAM 33 and resetting each flag and counter is executed (step 100) to prepare for the following processing.

Next, the DC motor 12 is driven until the second throttle opening θs indicates a fully open state, and the second throttle valve 14 is always fully opened at the start of the slip control of this embodiment or when the slip control is not performed. Processing is performed (step 110).

Next, it is determined by the opening degree of the first throttle valve 10 whether the vehicle is in an acceleration state that requires acceleration slip control (step 12).
0).

In the above determination, when it is determined that the first throttle valve 10 is not fully closed and acceleration slip control is required, the rotational speed VWF of the idler wheel corresponding to the vehicle speed in various operating conditions required for control is The detection values of the left and right idle wheel speed sensors 27 and 28 are averaged, the right drive wheel rotation speed VWRR is obtained from the detection value of the right drive wheel speed sensor 29a, and the acceleration of the VWRR is calculated.
The WRR is obtained from the change state of VWRR per unit time, the left drive wheel rotation speed VWRL and the acceleration WRL of the VWRL are obtained from the detection value of the left drive wheel speed sensor 29b, and the first throttle valve 1
A process of obtaining the opening degree θM of 0 from the detection value of the first throttle opening sensor 16 and the opening degree θs of the second slot valve 14 from the detection value of the second throttle opening sensor 17 is performed (step 130). .

Next, it is determined whether or not the rotational speed VWF of the idler wheel has reached the upper limit speed VMAX (for example, 100 Km / h) for performing the slip control of this embodiment (step 140).

When it is determined in the above determination that VMAX> VWF, the slip control shown below is performed (steps 150 to 290).

First, the drive wheel rotational speed VWR that is the target of slip control is determined by comparing the right drive wheel rotational speed VWRR and the left drive wheel rotational speed VWRL (step 150). As a result of the comparison, the rotation speed of the larger drive wheel is set to VWR (step 16).
0 or 220).

Hereinafter, the description will be given based on the right drive wheel rotation speed VWRR. The control when the left driving wheel rotation speed VWRL is larger (steps 220 to 250) is the same as the control when the VWRR is larger (steps 160 to 190), and therefore the description is omitted. .

Next, when the driving wheels are in the decelerating state, the processing for virtualizing the driving wheel speed correction value Vwr is performed (steps 170 to 190). In the processing, the driving wheel speed correction value Vwr which is regarded as the rotation speed of the driving wheels and is used as a comparison value when slip control is performed is calculated by the formula of Vwr = K1 VWRR + K2WRR (K1, K2 are predetermined coefficients) during deceleration ( Step 180), on the other hand, V during acceleration
Substitute VWRR for wr (step 190). In the timing chart of FIG. 7, the Vwr characteristic in the case of the deceleration processing is
It is indicated by a dotted line in the curve. By the processing during the deceleration, the correction value Vwr becomes smaller than the actual drive wheel rotation speed VWR and reaches the lower limit slip rotation speed ΔVso as shown in the figure.

Next, the upper limit slip rotation speed ΔVSC that reverses the torque applied to the drive wheels from the increasing state to the decreasing state, or the lower limit slip rotation speed ΔVS that reverses the torque to the increasing state from the decreasing state.
Set O (step 195). The setting routine will be described in detail with reference to FIG. In the routine, first, it is judged whether or not the value obtained by multiplying the idle wheel rotation speed VWF and the upper limit slip rate KSC is larger than the upper limit slip rotation speed ΔVSC1 (step 300), and according to the result, ΔVSC
Is set. The judgment result is VWF × KSC> ΔV
If it is SC1, VW is added to the upper limit slip rotation speed ΔVSC.
The value of F × KSC is set (step 310), while VWF × K
If SC ≦ ΔVSC1, ΔVSC1 is set to ΔVSC (step 340).

Next, regarding the setting of the lower limit slip rotation speed ΔVSO,
It is determined whether or not a value obtained by multiplying VWF by the lower limit slip ratio KSO is higher than the lower limit slip rotation speed ΔVSO1 (step 320), and ΔVSO is set according to the result. When the determination is VWF × KSO> ΔVSO1,
Lower limit slip rotation speed ΔVSO is set to VWF × KSO (step 330), while if VWF × KSO ≦ ΔVSO1, ΔVSO is set to ΔVSO1 (step 350). The time point at which the ΔVSO value is switched according to the result of comparison with the ΔVSO1 is time point T2 in FIG. By switching the above ΔVSC, ΔVSC1 is set to ΔVSC before the time point T1, and VWF × KSC is set to ΔVSC after the time point T1. On the other hand, by switching ΔVSO, ΔVSO is set to ΔVSO1 before time T2, and VWF × KSO is set to ΔVSO after time T2. That is, a constant slip control range width is set at a speed equal to or lower than a predetermined speed, while a slip control range width that becomes wider as the speed increases at a portion exceeding the predetermined speed is set.

Next, after the routine of FIG. 6 is completed, return to FIG.
Open and close the throttle valve 14 (step 200
Through 290). In the processing, when the drive wheel speed correction value Vwr is larger than the value obtained by adding the upper limit slip rotation speed ΔVSC to the idle wheel rotation speed VWF (step 200), that is, when it is determined that the slip is equal to or more than a predetermined value, In order to reduce the output torque and make the slip smaller than the predetermined value, the second throttle valve 14 is driven to close in the closing direction until the maximum closed position θsclose (for example, fully closed) is reached (step 210). On the other hand, when Vwr is smaller than the value obtained by adding VVSO to VWF (step 260), that is, when it is determined that the slip is not more than the predetermined value, the output torque is increased to make the slip larger than the predetermined value. The second throttle valve 14 to the first
The valve is driven to open until it coincides with the throttle valve opening θM (step 280). The valve opening speed is ΔVW which is a value obtained by subtracting the idle wheel rotation speed VWF from the drive wheel rotation speed VWR.
The motor speed is proportional to (slip 270). The motor voltage VM applied to the DC motor 12 is Δ from the predetermined motor voltage B.
A value obtained by subtracting the value obtained by multiplying VW by a predetermined coefficient K3, that is, VM = -K3
It is set to the value indicated by ΔVW + B. As shown in FIG. 8, the characteristic of the VM is that the VM becomes smaller as the ΔVW value becomes larger. Therefore, when the fall of VWR becomes gentle and VWR and VWF become equal (when the tire grips the road surface), the shock can be reduced and smooth slip control can be performed. As a result of the opening / closing valve drive of the second throttle valve 14, when the drive wheel speed correction value Vwr is within the range of VWF + ΔVSC or less and VWF + ΔVSO or more, the opening degree of the second throttle valve 14 is maintained (step 300). ).

When the above-mentioned on-off valve drive is performed and the slip converges within a predetermined range, the second throttle valve opening degree θS and the first throttle valve opening degree θM come to coincide with each other, and then the driving wheel acceleration WR also. Converges to 0. When the time TS that has been transiting coincident with each other has passed the predetermined time TOP, it is determined that the slip control is no longer necessary (step 290) and the second throttle valve 14 is fully opened (step 110). The predetermined time TOP is set to the time when the slip convergence is completed within the predetermined range. As a result of the above convergence, the time point at which the coincidence between θS and θM is started is the time point T3 in FIG. 7, and when the predetermined time TOP has passed after T3, that is, when the drive wheel speed correction value Vwr is converged, the time point is T4. The second opening / closing valve slip control of the second throttle valve 14 is terminated, and the second
Throttle valve 14 is fully open.

The upper limit slip rotation speed ΔVSC1 and the lower limit slip rotation speed ΔVSO, which are various predetermined values used in the above embodiment,
1. The upper limit slip ratio KSC and the lower limit slip ratio Kso are determined to be suitable values by experiments.

By using this embodiment described above, in the actual slip control by increasing / decreasing the output torque of the engine 1 performed by the second throttle valve 14, a constant slip value range, that is, a constant slip value, is maintained while the vehicle speed is low. Since the control is performed within the range width, it is possible to prevent malfunction due to sudden changes in vehicle speed and the like. On the other hand, at medium and high speeds, the control is performed in a constant slip ratio range, that is, the control range width increases as the vehicle speed increases, so that the most effective slip ratio, for example, slip ratio = -0.1, is aimed at. The slip can be controlled.

Furthermore, since the second throttle valve 14 is used, even if an abnormality occurs in the second throttle valve 14, the control can be performed using the first throttle valve 10, so the safety is high,
Moreover, since the intake air amount can be adjusted in a large range, a wide range of torque control can be obtained.

Therefore, by using this embodiment, it is possible to provide a slip control device for a vehicle which is excellent in safety, wide-range controllability, and ability to maintain an optimum slip state.

[Effects of the Invention] As described above, by using the present invention, the range of slip control can be widened within a predetermined range of vehicle speed as the vehicle speed increases. Therefore, for example, at middle and high speeds, control can be performed by increasing or decreasing the output torque of the engine M7 so as to move it into the slip range where the road frictional force can be maximized. As a result, stable from the low speed to the high speed, and the best acceleration can be obtained. Further, it is not necessary to improve the slip value calculation accuracy in the low speed range, and the optimum acceleration slip control can be performed without increasing the cost.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of the basic configuration of the present invention, and FIG.
FIG. 3 is a diagram for explaining the relationship between the slip ratio and the road surface frictional force, FIG. 3 is a schematic configuration diagram of the embodiment, FIG. 4 is a block diagram of a control system of the embodiment, and FIG. 5 is a flow chart of a control program of the embodiment. FIG. 6 is a flowchart of a slip range value setting routine of the embodiment, FIG. 7 is a timing chart of the embodiment,
FIG. 8 is a graph showing characteristics during valve opening control. M1 …… idling wheel M2 …… idling wheel rotation speed detection means M3 …… driving wheel M4 …… driving wheel rotation speed detection means M5 …… slip value calculation means M6 …… slip range value setting means M7 …… engine M8 …… Output torque increasing / decreasing part M9 …… Slip control means 1 …… Engine 14 …… Second throttle valve 27 …… Left idle wheel speed sensor 28 …… Right idle wheel speed sensor 29a …… Right drive wheel speed sensor 29b …… Left drive Wheel speed sensor 30 ... Drive control circuit

Claims (1)

[Claims] Claim: What is claimed is: 1. An idle wheel rotational speed detecting means for detecting the rotational speed of an idle wheel of a vehicle; a drive wheel rotational speed detecting means for detecting the rotational speed of a drive wheel of a vehicle; and detection of the idle wheel rotational speed detecting means. A slip value calculating means for calculating the slip value of the driving wheel from the magnitude relationship between the calculated value obtained from the calculated value and the calculated value obtained from the detected value of the driving wheel rotational speed detecting means, and a predetermined upper limit Slip range value setting means for setting a predetermined slip range value consisting of a slip value and a predetermined lower limit slip value, and when the slip value is equal to or more than the predetermined upper limit slip value,
Slip control means for controlling the output torque increasing / decreasing portion of the engine to reduce the output torque, and, when the slip value is equal to or less than a predetermined lower limit slip value, for controlling the output torque increasing / decreasing portion of the engine to increase the output torque. In the slip control device for a vehicle, the slip range value setting means maintains the predetermined slip range value constant in a predetermined low vehicle speed state, and increases the vehicle speed by the predetermined slip range value in a predetermined medium and high vehicle speed. A slip control device for a vehicle, wherein the slip control device is configured to be widened accordingly.